Lesson Ten What role does energy play in chemical reactions? Science Asking Questions, Developing Models, Investigating, Analyzing Data and Obtaining, Evaluating, and Communicating Information ENGLISH LANGUAGE ARTS Reading Informational Text, Writing an Explanation Grade 8 90 minutes PURPOSE Energy plays a major role in chemical reactions. It takes energy to break bonds and energy is released when new bonds are formed. Some chemical reactions require more energy than others. In this lesson, students will conduct an investigation of several chemical reactions to explore the role that energy plays. Students use their prior learning to construct a written explanation of energy in chemical reactions. STANDARDS Common Core State Standards Determine the central ideas or conclusions of a text; provide an accurate summary of the text distinct from prior knowledge or opinions. CCSS.ELA-LITERACY.RST.6-8.2 Follow precisely a multistep procedure when carrying out experiments, taking measurements, or performing technical tasks. CCSS.ELA- LITERACY.RST.6-8.3 Compare and contrast the information gained from experiments, simulations, video, or multimedia sources with that gained from reading a text on the same topic. CCSS.ELA-LITERACY.RST.6-8.9 Use precise language and domain-specific vocabulary to inform about or explain the topic. CCSS.ELA-LITERACY.WHST.6-8.2.D
STANDARDS Continued C o m m o n C o r e S ta te S ta n d a rd s C o nd u ct s h or t re s e a r c h p ro je ct s to a n s w e r a q ue s ti on (i nc lu d in g a s e lf- g e ne r a t e d q ue s t i on ), dr a w in g on s e v e ra l s o u rc e s a n d ge n e r a t in g a d d iti on a l r e la t e d, f o cu s e d q u e st ion s th a t a l low f o r m u lt ip le a v e n ue s of e x p lo ra t io n. C C S S.E L A - L IT E R A C Y. W H S T. 6-8. 7 N e x t G e n e ra ti o n S c i en c e S ta n d a rd s D e v e l op a m od e l th a t p re d ict s a nd de s c rib e s c h a n ge s in p a r ti cle m ot io n, te m p e r a t u r e, a nd s ta t e o f a pu r e s u bs t a n ce w h e n th e r m a l e n e rg y is a d d e d o r re m o v e d. M S- P S - 1-4 D e v e l op a n d u se a m o de l to de s cr ib e ho w th e t ot a l nu m b e r o f a to m s d oe s no t ch a n g e i n a ch e m ic a l r e a ct ion a n d t h u s m a s s is co n se r v e d. M S - P S - 1-5 C h e m ica l R e a ct io ns. PS 1. B S u b s t a n ce s re a ct ch e m ic a ll y in c ha ra ct e r is t i c w a y s. I n a ch e m ic a l p ro ce s s, th e a t o m s t ha t m a k e u p t he o rig in a l s u b st a n ce s a r e r e g ro u pe d i n t o d if f e r e n t m ole c u le s, a n d t h e s e n e w s ub s t a n c e s h a v e d if f e r e nt p r op e r t ie s f r om th o s e o f r e a c ta n t s. T h e t ot a l nu m b e r o f e a ch t y p e o f a t o m is c on s e rv ed, a n d t hu s t h e m a ss d oe s no t ch a n g e. S c i en c e a n d E n g i n e er i n g P r ac t i c e s A s k in g q u es t ion s a n d d e f i ni ng pr ob le m s D e v e l op in g a nd us in g m od e ls P la n n in g a n d c a r ry in g o ut in v e s ti ga tio n s A n a ly z in g a n d i nt e rp r e t in g d a t a O bt a in in g, e v a lu a ti ng, a n d co m m u n ica t in g in f o r m a t i on 2
LEARNING GOALS Understand that catalysts are necessary for chemical reactions. Understand the difference between an endothermic and an exothermic reaction. Understand that energy is released when bonds are broken. SUCCESS CRITERIA 1 Identify the differences between endothermic and exothermic reactions. 2 Explain the role of catalysts in accelerating chemical reactions. 3 Investigate reactions. SUMMARY OF LESSON TASKS 1 Complete Double Entry Journal. 2 Read and annotate: Energy Changes in Chemical Reactions. 3 Conduct investigation. 4 Write an explanation. Culminating task Write a laboratory report of the investigation. Include an explanation of the role of energy in endothermic and exothermic reactions. Use the data from your investigation and information from previous lessons to support the explanation. Cite your sources. PART I: INTRODUCTION INTRODUCE THE TOPIC Ask students to think about what they have learned about chemical reactions in previous lessons. Ask students, What role does energy play in chemical reactions? 3
COMPLETE A DOUBLE ENTRY JOURNAL Ask students to locate Middle School Chemistry Chapter 6 and use the information they have read related to energy in chemical reactions (pages 685 and 686). Students complete a Double Entry Journal in their Science Notebooks. In the first column, students should record and paraphrase notes related to the initial question. In the second column, students include supporting details and source information. SUCCESS CRITERION EVIDENCE-GATHERING OPPORTUNITY Identify and describe the differences between endothermic and exothermic reactions. Explain the role of catalysts in accelerating chemical reactions. As students review the text they read in previous lessons, check that students are recording information related to energy (e.g., reaction rate, temperature, exothermic and endothermic reactions, catalysts). ANTICIPATED RESPONSE PEDAGOGICAL ACTION If you notice that students record main ideas related to energy but experience difficulty with identification of supporting details, or vice versa, support them by completing an example together. Read a paragraph or two with the student and show how you would identify a main idea, or supporting detail. It is important to think aloud in this example to make your thought process visible to students. PART II: guided practice READ AND ANNOTATE Provide students with a copy of Energy Changes in Chemical Reactions (http://www.middleschoolchemistry.com/pdf/chapter6/6.7_student.pdf). Students read and annotate the investigation activity handout, focusing on the procedures, in preparation for the investigation. 4
CONDUCT INVESTIGATION Students work with a partner to conduct the investigation. Remind students to formulate hypotheses for each Question to Investigate prior to proceeding with the investigation. Students continue to use their Science Notebooks to record observations, complete data analysis and interpretation, and write a conclusion that explains investigation findings. SUCCESS CRITERION EVIDENCE-GATHERING OPPORTUNITY Investigate reactions. As students work together to complete the investigation, listen to the conversation. Check that students are discussing the data they have gathered and are beginning to use content vocabulary (exothermic, endothermic, catalyst, rate of the reaction, etc.). You are looking for evidence that students understand the role of energy in chemical reactions. ANTICIPATED RESPONSE PEDAGOGICAL ACTION If you notice student move through the investigation completing the steps procedurally but with little to no engagement with the ideas that guide the explorations, ask questions to push student to think about the procedures and connect these with the learning goals of the lesson. Questions might include: Why does temperature matter in a chemical reaction? How does exploring temperature help us understand chemical reactions? What is happening to the molecules in these reactions? PART III: culminating task WRITE EXPLANATION In the final task, students write an explanation describing the role of energy in endothermic and exothermic reactions. The explanation: provides an accurate description of the the role of energy in endothermic and exothermic reactions (it takes energy to release bonds, endothermic reactions require 5
more energy to break bonds vs. exothermic reactions, exothermic reactions release more energy than endothermic reactions) illustrates logical reasoning in conclusions includes appropriate use of content vocabulary references relevant and appropriate evidence to support explanation SUCCESS CRITERION EVIDENCE-GATHERING OPPORTUNITY Review individual students Science Notebooks to gather additional evidence of student learning. Check that students have recorded hypotheses, procedures, and observation notes. When reviewing observation notes, check that they are descriptive and precise. ADDITIONAL LESSON RESOURCES B ac kg r ou n d Middle School Chemistry Teacher Guide http://www.middleschoolchemistry.com/pdf/chapter6/teacher_backgroun d_6.7.pdf Middle School Chemistry Teacher Text http://www.middleschoolchemistry.com/lessonplans/chapter6/lesson7 6
DOUBLE ENTRY JOURNAL What role does energy play in chemical reactions? How do you know? Record your evidence and cite your sources. 7